Table of Contents
Advertisement
www.WorkshopManuals.co.uk
Section F
66 - 10
Powershift Gearbox
Pressure Testing - Clutches
Individual Clutch Leakage Test
When testing individual clutch pressures it is necessary to
isolate the clutch being tested. So for instance, on a 6 speed
gearbox, to check the forward low clutch T we must select
2nd gear forward - this would energise the forward low (T)
and layshaft (Z) clutches. Because we only want to check
the forward low (T) clutch pressure and not the layshaft (Z)
clutch pressure, remove the electrical connector to the 6
speed clutch solenoid Zs BEFORE selecting 2nd gear.
Use the table below to determine which solenoid electrical
connectors should be removed when pressure testing
individual clutches. Note that as the first 3 forward and
reverse gears utilise all clutches, there is no need to select
other gears when testing for leakage.
6 Speed Gearbox
Gear
Clutches Engaged (Solenoids Energised)
Selected
1st Forward
6 Speed & Layshaft - X,Z
2nd Forward
Forward Low & Layshaft - T,Z
3rd Forward
Forward High & Layshaft - U,Z
1st Reverse
Reverse Low & Layshaft - W,Z
2nd Reverse
Reverse High & Layshaft - V,Z
3rd Reverse
Reverse Low & Mainshaft - W,Y (Ws,Ys)
4 Speed Gearbox
Gear
Clutches Engaged (Solenoids Energised)
Selected
1st Forward
Forward Low & Layshaft - T,Z
2nd Forward
Forward High & Layshaft - U,Z
3rd Forward
Forward Low & Mainshaf - T,Y
1st Reverse
Reverse Low & Layshaft - W,Z
2nd Reverse
Reverse High & Layshaft - V,Z
3rd Reverse
Reverse Low & Mainshaft - W,Y (Ws,Ys)
Ts
Us
Ss
Ys
Zs
Xs
9803/3280
Transmission
Service Procedures
(Xs,Zs)
(Ts,Zs)
(Us,sZ)
(Ws,Zs)
(Vs,Zs)
(Ts,Zs )
(Us,Zs)
(Ts,Ys)
(Ws,Zs)
(Vs,Zs)
Ws
Vs
Purchased from www.WorkshopManuals.co.uk
In the following procedures the forward low clutch (T) is
tested, therefore in step 2 a pressure gauge is connected to
the forward low clutch test point.
When testing other suspect clutches connect a gauge to the
relevant suspect clutch test point. Because the forward low
clutch is suspect, a gear must be selected that will use the
forward low clutch, in this instance 2nd gear forward.
Note: When testing the 2/4WD clutch remove the feed pipe
R and fit service tool. This pipe incorporates a test point.
Replace the original pipe when testing is complete.
1
Stop engine, connect a 0-20 bar (0-300 lbf/in
gauge to test connector A, (mainline pressure test
point).
2
Connect a 0-20 bar (0-300 lbf/in
test connector T (forward low ratio clutch test point).
3
Remove the layshaft clutch solenoid feed connector Zs,
at the solenoid control valve. This ensures that only the
forward low clutch T is energised when 2nd gear
forward is selected.
Make sure that both sides of all four wheels are
4
chocked. Apply the footbrake and parking brake.
Note: When fully engaged, the parking brake electrically
disconnects the transmission drive; this prevents the
machine from being driven with the parkbrake on. Therefore,
so that we can complete the test, move the parkbrake lever
fractionally forward until the warning light is just
extinguished; hold the lever in this position for the duration
of the test. DO NOT move the lever too far forward,
otherwise the parkbrake will not be fully operational.
Alternatively, disconnect the switch at the park brake.
5
Start engine and run at 1000 rev/min, select 2nd gear
forward. Note the pressure readings on both gauges,
which should not vary by more than 0.7 bar (10 lbf/in
If the difference on the gauges is greater than 0.7 bar
(10 lbf/in
2
) do the following:
a
Stop the engine and interchange the gauges.
b
Start the engine and run at 1000 rev/min, select
2nd gear forward. If the difference on the gauges is
still greater than 0.7 bar (10 lbf/in
forward low clutch for servicing.
If after interchanging the gauges, the readings are
c
different than at step 5, have the gauges calibrated
and repeat the testing procedure.
Section F
66 - 10
2
) pressure
2
) pressure gauge to
2
).
2
) dismantle the
Issue 1
Advertisement
Table of Contents
